Dr Charnchai Chanvorachaikul, the director of the hospital, said Wednesday that the baby was admitted for treatment at the hospital at about 9 pm Tuesday night.
The baby boy suffers multiple knife wounds on the right side of the chest and abdomen and with a punctured lung.
Dr Charnchai Chanvorachaikul said doctors had to administer a respirator to help the baby breathe, a device to pump air out of the punctured lung and operate on his stomach.
Saying the baby was still in critical condition with a 50:50 percent chance of survival.
The baby was miraculously rescued by Mrs Khachit Klongyuti, wife of the assistant village head of Ban Khornsawan. She later told reporters that she went to the rice field outside the village at about 4 pm and heard what sound like gecko squeaking from the foot of a eucalyptus tree.
She saw a newly-covered mound where the sound came from and started digging and found the baby lying with his face down. She then immediately rushed to baby to Waeng Yai district hospital and notified the village head as well as the police.
The baby was later taken to the provincial hospital as the Waeng Yai hospital was not adequately equipped to treat the patient.
An investigation was launched by the police to find out the perpetrator.